Claude Fable 5 system prompt leaked on GitHub within 24 hours, exposing 120,000 characters of hidden rules, safety limits, and secret restrictions.

Anthropic's prompt caching can reduce Claude API input costs by up to 90%, but developers must structure prompts correctly to ...

Master Claude prompts to transform vague AI outputs into precise, expert-level responses using role play, constraints, and ...

Anthropic’s AI coding agent silently encoded proxy hostnames and Chinese timezone data into invisible Unicode characters ...

This is the 2nd part of my analysis on Anthropic Claude and its system-wide prompt, focusing on the mental health directives. An AI Insider analysis and scoop.

It says that its AI models are backed by ‘uncompromising integrity’ – now Anthropic is putting those words into practice. The company has pledged to make details of the default system prompts used by ...

I was the bottleneck the whole time ...

A security researcher, working with colleagues at Johns Hopkins University, opened a GitHub pull request, typed a malicious instruction into the PR title, and watched Anthropic’s Claude Code Security ...

Last week, Anthropic released the system prompts — or the instructions for a model to follow — for its Claude family of models, but it was incomplete. Now, the company promises to release the system ...

System-level instructions guiding Anthropic's new Claude 4 models tell it to skip praise, avoid flattery and get to the point, said independent AI researcher Simon Willison, breaking down newly ...

For as long as AI Large Language Models have been around (well, for as long as modern ones have been accessible online, anyway) people have tried to coax the models into revealing their system prompts ...

Learn how to fix Claude Code's most annoying behaviors using prompt submit hooks to eliminate flattery, reduce verbosity, and ...